American Society of Mammalogists

New Evidence on the Origin of the Fox, Urocyon littoralis clementae, and Feral Goats on SanClemente Island, CaliforniaAuthor(s): Donald Lee JohnsonSource: Journal of Mammalogy, Vol. 56, No. 4 (Nov., 1975), pp. 925-928Published by: American Society of MammalogistsStable URL: http://www.jstor.org/stable/1379668 .

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GENERAL NOTES GENERAL NOTES

TABLE 1.-External and cranial measurements of the five known specimens of Sturnira thomasi.

co

00 0 + 113~-" el

c o o< o o o

Measurement d H H H .- H.e

Length of head and body 80 82 73 80 81 Length of hind foot 16 13 13 15 15 Length of ear 18 19 16 17 19 Length of forearm 48.1 45.9 46.4 46.1 47.7 Greatest length of skull 26.2 25.3 24.4 24.9 25.1 Condylobasal length 24.7 23.3 22.4 22.9 23.6 Zygomatic breadth 12.7 12.1 11.9 12.2 12.5 Mastoid breadth 12.1 11.7 11.2 11.7 11.8 Breadth of braincase - 9.8 9.5 9.8 9.6 Interorbital constriction 6.3 5.7 5.5 5.9 6.0 Postorbital constriction 6.0 5.7 5.6 5.5 5.9 Length of maxillary toothrow 7.7 7.0 6.7 6.9 6.9 Breadth across upper molars 8.2 8.1 7.7 8.0 8.0 Length of mandibular toothrow (i-m2) 7.8 7.7 7.7 7.7 7.8

* Measurements after de la Torre and Schwartz (1966:301).

TABLE 1.-External and cranial measurements of the five known specimens of Sturnira thomasi.

co

00 0 + 113~-" el

c o o< o o o

Measurement d H H H .- H.e

Length of head and body 80 82 73 80 81 Length of hind foot 16 13 13 15 15 Length of ear 18 19 16 17 19 Length of forearm 48.1 45.9 46.4 46.1 47.7 Greatest length of skull 26.2 25.3 24.4 24.9 25.1 Condylobasal length 24.7 23.3 22.4 22.9 23.6 Zygomatic breadth 12.7 12.1 11.9 12.2 12.5 Mastoid breadth 12.1 11.7 11.2 11.7 11.8 Breadth of braincase - 9.8 9.5 9.8 9.6 Interorbital constriction 6.3 5.7 5.5 5.9 6.0 Postorbital constriction 6.0 5.7 5.6 5.5 5.9 Length of maxillary toothrow 7.7 7.0 6.7 6.9 6.9 Breadth across upper molars 8.2 8.1 7.7 8.0 8.0 Length of mandibular toothrow (i-m2) 7.8 7.7 7.7 7.7 7.8

* Measurements after de la Torre and Schwartz (1966:301).

Our females (two adults, one young adult, and one juvenile) all are somewhat smaller than the male holotype (see Table 1), but otherwise resemble it with the exception of uniformly lacking a lower third molar. Two of the females lack this minute tooth on both sides, one has the tooth present on the left side but absent on the right, whereas the fourth possesses the tooth in both rami. The two adults (both of which were lactating) are dark brownish dorsally; one is also dark brownish on the venter but the other is paler, having a greater suffusion of buff. The young adult is paler dorsally than are the adults and pale buffy brown ventrally, whereas the juvenile (unfused phalangeal epiphyses) is dark gray- ish brown dorsally and dark ventrally, with hairs on the venter frosted with buff or gray.

In our view, by virtue of its large size and elongate skull in combination with other characters as described by de la Torre and Schwartz (op. cit.), Sturnira thomasi differs sufficiently from other members of the genus occurring in the Lesser Antilles to the south of Guadeloupe (specimens examined from Dominica, Martinique, St. Lucia, and St. Vin- cent) to command recognition as a distinct species.-HUGH H. GENOWAYS AND J. KNOX JONES, JR., The Museum and Department of Biological Sciences, Texas Tech University, Lubbock, 79409. Submitted 8 October 1974. Accepted 2 March 1975.

NEW EVIDENCE ON THE ORIGIN OF THE FOX, UROCYON LITTORALIS CLEMENTAE, AND FERAL GOATS ON SAN CLEMENTE ISLAND, CALIFORNIA

The island fox (Urocyon littoralis) of the California Channel Islands has long interested evolutionary biologists, mammalogists, and biogeographers. This interest stems in part because the island fox differs in several morphologic characters from the mainland gray fox (U. cinereoargenteus), most notably in its much smaller stature. The island fox is also of zoogeographic interest because six endemic races occur on a like number of islands that

Our females (two adults, one young adult, and one juvenile) all are somewhat smaller than the male holotype (see Table 1), but otherwise resemble it with the exception of uniformly lacking a lower third molar. Two of the females lack this minute tooth on both sides, one has the tooth present on the left side but absent on the right, whereas the fourth possesses the tooth in both rami. The two adults (both of which were lactating) are dark brownish dorsally; one is also dark brownish on the venter but the other is paler, having a greater suffusion of buff. The young adult is paler dorsally than are the adults and pale buffy brown ventrally, whereas the juvenile (unfused phalangeal epiphyses) is dark gray- ish brown dorsally and dark ventrally, with hairs on the venter frosted with buff or gray.

In our view, by virtue of its large size and elongate skull in combination with other characters as described by de la Torre and Schwartz (op. cit.), Sturnira thomasi differs sufficiently from other members of the genus occurring in the Lesser Antilles to the south of Guadeloupe (specimens examined from Dominica, Martinique, St. Lucia, and St. Vin- cent) to command recognition as a distinct species.-HUGH H. GENOWAYS AND J. KNOX JONES, JR., The Museum and Department of Biological Sciences, Texas Tech University, Lubbock, 79409. Submitted 8 October 1974. Accepted 2 March 1975.

NEW EVIDENCE ON THE ORIGIN OF THE FOX, UROCYON LITTORALIS CLEMENTAE, AND FERAL GOATS ON SAN CLEMENTE ISLAND, CALIFORNIA

The island fox (Urocyon littoralis) of the California Channel Islands has long interested evolutionary biologists, mammalogists, and biogeographers. This interest stems in part because the island fox differs in several morphologic characters from the mainland gray fox (U. cinereoargenteus), most notably in its much smaller stature. The island fox is also of zoogeographic interest because six endemic races occur on a like number of islands that

November 1975 November 1975 925 925

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JOURNAL OF MAMMALOGY

are scattered across some 240 linear kilometers of ocean, from San Miguel Island on the northwest to San Clemente Island on the southeast. The evolutionary history and zoogeo- graphical relations of the island fox have been discussed by Grinnell et al. (1937), Dickey (in Rogers, 1929: 445), Stock (1943), Norris (1951: 74), Vedder and Norris (1963), von Bloeker (1967), Savage (1967: 265), Orr (1968: 42), Remington (1971), and John- son (1972: 157-164).

The feral goats of the Channel Islands are of interest because they are voracious modi- fiers and destroyers of the indigenous vegetation, some elements of which are insular endemics. Goats occur only on Santa Catalina and San Clemente islands, but Farnham (1849) alleged that in the 1840's they also occurred on Santa Barbara and San Nicolas islands.

This note deals with San Clemente Island, and brings new evidence to the long-standing problem of when and how the foxes and goats originated on it. Except for San Clemente Island, there is no reason to doubt that U. littoralis was present on all the larger Channel Islands in prehistoric time. The problematic history of the foxes and goats on San Clemente Island stems from a published conversation that mammalogist J. S. Dixon had in 1920 with a longtime resident of the island, Salvador Ramirez, who claimed to have introduced foxes and goats from Santa Catalina Island in 1875 (Grinnell et al., 1937: 464). Light was shed on the matter recently when this writer discovered several unpublished 19th century letters, hand-written by Coast Survey Assistant W. E. Greenwell to his superior, A. D. Bache, then the superintendent of the Coast Survey. Greenwell was charged with establishing triangulation stations on San Clemente Island during the early 1860's. In one letter Greenwell (1860b) describes the general character of San Clemente Island and states: "Now with the exception of a small island fox no living animal [mammal] is found. . . ." This letter is dated 2 September 1860, 15 years before Ramirez claimed to have brought his fox pair and goats to the island in 1875. Greenwell's observation suggests strongly that U. littoralis was present on all six of the largest Channel Islands, including San Clemente, in prehistoric time (how the fox came to be on San Clemente and the other islands in late Quaternary time is a matter beyond the scope of this paper).

Although the fox dilemma is resolved, a goat dilemma remains. When were goats intro- duced to San Clemente? Were they already present in the 1840's as alleged by Farnham (1849: 107) and somehow overlooked by Greenwell later? Or did Ramirez first introduce them in 1875? Or, were goats first introduced early in the 19th century, driven to extinction between the 1840's and 1860, then reintroduced by Ramirez?

Although unequivocal answers to these questions go begging, a cautious sifting of the evidence is instructive. First, Farnham's allegation that Santa Barbara, San Nicolas, and San Clemente islands were "densely populated with goats" in the mid-19th century is not verified by other accounts (Ellison, 1937; Hardacre, 1880; Greenwell, 1858a, 1858b, 1858c, 1860a, 1860b, 1862a, 1862b; Phillips, 1927: 108). From 1835 to 1853, for example, the only large land mammals known to have inhabited San Nicolas Island were dogs, foxes, and one Indian woman (Ellison, 1937; Hardacre, 1880). In reading Farnham's account it is clear that he never visited or came within eyesight of the three islands about which he spoke. Therefore, his statement must have been based on information provided by others. Farnham wrote in the 1840's when practically nothing was in print on the subject, and word-of-mouth information about what animal lived on which island is of low credi- bility. I might add that without reference materials even modem investigators are hard- pressed to correctly match present feral animals with the islands on which they occur.

Furthermore, it is clear from Greenwell's letters that he and his assistants intermittently camped on, trod, and surveyed the length of San Clemente over a period spanning at least two years, and had goats or other large mammals been present it seems certain that they or their spoor would have been noticed. In fact, Greenwell (1862a) did note ". . . about

150 head of wild sheep . . ." subsequent to when he first noted the fox (when the sheep

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GENERAL NOTES

were first introduced is not known). At any rate, Greenwell made no mention of goats in his reports and letters, and it seems unlikely that he or his assistants would have mis- taken goats for sheep, although this remains a possibility.

Finally, if it is assumed that, as with the fox, Ramirez did bring goats to San Clemente in 1875 as he intended, he apparently was motivated in part by his belief that neither animal was then present on the island. In this regard the small indigenous fox and its spoor might conceivably have been somehow overlooked for a short time by Ramirez, who was then presumably a newcomer to the island, but he could hardly have missed goats had they been present. Modern visitors to the island are confronted with abundant evi- dence of goats in the form of droppings, hair, footprints, and even their smell, not to mention the goats themselves. Had feral goats been present in 1875 or before, even in far fewer numbers than now, such signs surely would have been apparent to Ramirez and, especially, to Greenwell and company.

I conclude that the fox (U. littoralis clementae) was present on San Clemente Island in prehistoric time and, contrary to one published account, was not originally introduced to the island by western man in 1875. However, a pair of U. littoralis catalinae from Catalina Island may have been brought to San Clemente at this time.

Conclusions about the first introductions of goats to San Clemente cannot be considered definite or unequivocal. Yet, because several early reports omitted mention of goats but listed foxes and feral sheep, and because goats presumably were brought to San Clemente Island in 1875, the latter date probably marks the time of their introduction. Sheep were introduced to the island prior to 1862.

I thank Professors C. S. Alexander, C. Bennett, and J. Thompson for helpful criticisms.

LITERATURE CITED

ELLISON, W. H. (ed.). 1937. The life and adventures of George Nidever, 1802-1883. Univ. California Press, Berkeley, 129 pp.

FARNHAM, T. J. 1849. Life, adventures, and travels in California. Nafis and Cornish, New York, 468 pp.

GREENWELL, W. E. 1858a. Letter of 30 June. Coast Survey, Superintendent's Report (original), Sections I-II, Volume 23, Record Group 23, National Archives.

1858b. Letter of 31 July. Coast Survey, Western Coast Special Surveys (1855- 58) and Lighthouse, Volume 16, Record Group 23, National Archives.

1858c. Letter of 14 August. Coast Survey, Superintendent's Report (original), Sections I-II, Volume 23, Record Group 23, National Archives.

. 1860a. Letter of 4 July. Coast Survey, Western Coast Special Surveys and Lighthouse, Volume 13, Record Group 23, National Archives.

1860b. Letter of 2 September. Coast Survey, Superintendent's Report (original), Volume 22, Record Group 23, National Archives.

1862a. Letter of 5 June. Coast Survey, Superintendent's Report, Appendix and Sketches, Volume 9, Record Group 23, National Archives.

. 1862b. Letter of 28 September. Coast Survey, Superintendent's Report, Ap- pendix and Sketches, Volume 9, Record Group 23, National Archives.

GRINNELL, J., J. S. DIXON, AND J. M. LINSDALE. 1937. Fur bearing animals of California. Univ. California, Berkeley, 2:1-464.

HARDACRE, E. H. 1880. Eighteen years alone. Scribner's Monthly, 20:657-664.

JOHNSON, D. L. 1972. Landscape evolution on San Miguel Island, California. Xerox Univ. Microfilms, Ann Arbor catalog no. 73-11902, 480 pp.

NORRIS, R. M. 1951. Marine geology of the San Nicolas Island region, California. Un- published Ph.D. thesis, Scripps Instit. Oceanog., 124 pp.

ORR, P. C. 1968. Prehistory of Santa Rosa Island. Santa Barbara Mus. Nat. Hist., 253 pp.

November 1975 927

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JOURNAL OF MAMMALOGY JOURNAL OF MAMMALOGY

PHILLIPS, M. J. 1927. History of Santa Barbara County, California. S. J. Clarke Pub. Co., Los Angeles, 1:107-114.

REMINGTON, C. L. 1971. Natural history and evolutionary genetics of the California Islands. Discovery, 7:2-18.

ROGERS, D. B. 1929. Prehistoric man on the Santa Barbara Coast. Santa Barbara Mus. Nat. Hist., 452 pp.

SAVAGE, J. M. 1967. Discussion of the significance of distribution patterns. P. 265, in Proc. Symp. Biol. California Islands (R. N. Philbrick, ed.), Santa Barbara Botanic Garden, Santa Barbara.

STOCK, C. 1943. Foxes and elephants of the Channel Islands. Los Angeles County Museum Quart., 3:6-9.

VEDDER, J. G., AND R. M. NORmus. 1963. Geology of San Nicolas Island, California. Geological Surv. Prof. Paper 269:1-65.

VON BLOEKER, J. R., JR. 1967. The land mammals of the Southern California Islands. Pp. 245-263, in Proc. Symp. Biol. California Islands (R. N. Philbrick, ed.), Santa Barbara Botanic Garden, Santa Barbara.

DONALD LEE JOHNSON, Department of Geography, University of Illinois, Urbana 61801. Submitted 14 August 1974. Accepted 1 March 1975.

ECOLOGICAL RELATIONSHIPS AND BREEDING BIOLOGY OF THE NUTRIA (MYOCASTOR COYPUS) IN THE TAMPA, FLORIDA, AREA

Nutria (Myocastor coypus) were first reported as exotics in Florida in the 1950's when feral animals were captured in the Panhandle and in the Hillsborough River drainage of west central Florida (Griffo, 1957). The Florida Panhandle colonies apparently resulted from the eastward expansion of populations along the Gulf Coast that originated in the Louisiana marshes (see Atwood, 1950; Lowery, 1974). By contrast, the colonies of nutria recorded from the Hillsborough River and other locations in peninsular Florida resulted from escapes or outright releases from abortive furfarming operations in the 1950's and later.

A study of the ecological relationships and breeding cycle of Myocastor coypus was ini- tiated in late 1972 and continued throughout 1973 in the vicinity of Brandon and Tampa in Hillsborough County, Florida. It became evident that nutria were exceedingly abundant in barnyard runoff canals and polluted holding ponds maintained by several large dairies in the Tampa Bay area. Florida State Health Department regulations require that all dairies keeping large numbers of cows in feeding lots construct a series of polishing pollution ponds to trap and settle out much of the excreta and other organic wastes

generated by dairy operation. In order to quantify the high nutria numbers observed, sampling was conducted in one

typical five-acre pollution pond and compared to the nutria density in another five-acre

unpolluted farm pond located about one mile away. At both ponds one-day shoots were conducted simultaneously by two groups of three

persons each, using rifles to harvest all nutria observed swimming or feeding in the ponds during a single eight-hour period. The results were surprising in that the pollution pond yielded 50 nutria (24.7 per surface hectare of water) and the unpolluted pond yielded only 12 nutria (5.9 per surface hectare of water) in the inventories. These numerical estimates are believed to be fairly close to the actual population present in each pond because no nutria were observed at either site on the day following the inventory. Such differences in the carrying capacity of nutrient-rich ponds versus unpolluted ponds was

observed repeatedly throughout the course of this study.

PHILLIPS, M. J. 1927. History of Santa Barbara County, California. S. J. Clarke Pub. Co., Los Angeles, 1:107-114.

REMINGTON, C. L. 1971. Natural history and evolutionary genetics of the California Islands. Discovery, 7:2-18.

ROGERS, D. B. 1929. Prehistoric man on the Santa Barbara Coast. Santa Barbara Mus. Nat. Hist., 452 pp.

SAVAGE, J. M. 1967. Discussion of the significance of distribution patterns. P. 265, in Proc. Symp. Biol. California Islands (R. N. Philbrick, ed.), Santa Barbara Botanic Garden, Santa Barbara.

STOCK, C. 1943. Foxes and elephants of the Channel Islands. Los Angeles County Museum Quart., 3:6-9.

VEDDER, J. G., AND R. M. NORmus. 1963. Geology of San Nicolas Island, California. Geological Surv. Prof. Paper 269:1-65.

VON BLOEKER, J. R., JR. 1967. The land mammals of the Southern California Islands. Pp. 245-263, in Proc. Symp. Biol. California Islands (R. N. Philbrick, ed.), Santa Barbara Botanic Garden, Santa Barbara.

DONALD LEE JOHNSON, Department of Geography, University of Illinois, Urbana 61801. Submitted 14 August 1974. Accepted 1 March 1975.

ECOLOGICAL RELATIONSHIPS AND BREEDING BIOLOGY OF THE NUTRIA (MYOCASTOR COYPUS) IN THE TAMPA, FLORIDA, AREA

Nutria (Myocastor coypus) were first reported as exotics in Florida in the 1950's when feral animals were captured in the Panhandle and in the Hillsborough River drainage of west central Florida (Griffo, 1957). The Florida Panhandle colonies apparently resulted from the eastward expansion of populations along the Gulf Coast that originated in the Louisiana marshes (see Atwood, 1950; Lowery, 1974). By contrast, the colonies of nutria recorded from the Hillsborough River and other locations in peninsular Florida resulted from escapes or outright releases from abortive furfarming operations in the 1950's and later.

A study of the ecological relationships and breeding cycle of Myocastor coypus was ini- tiated in late 1972 and continued throughout 1973 in the vicinity of Brandon and Tampa in Hillsborough County, Florida. It became evident that nutria were exceedingly abundant in barnyard runoff canals and polluted holding ponds maintained by several large dairies in the Tampa Bay area. Florida State Health Department regulations require that all dairies keeping large numbers of cows in feeding lots construct a series of polishing pollution ponds to trap and settle out much of the excreta and other organic wastes

generated by dairy operation. In order to quantify the high nutria numbers observed, sampling was conducted in one

typical five-acre pollution pond and compared to the nutria density in another five-acre

unpolluted farm pond located about one mile away. At both ponds one-day shoots were conducted simultaneously by two groups of three

persons each, using rifles to harvest all nutria observed swimming or feeding in the ponds during a single eight-hour period. The results were surprising in that the pollution pond yielded 50 nutria (24.7 per surface hectare of water) and the unpolluted pond yielded only 12 nutria (5.9 per surface hectare of water) in the inventories. These numerical estimates are believed to be fairly close to the actual population present in each pond because no nutria were observed at either site on the day following the inventory. Such differences in the carrying capacity of nutrient-rich ponds versus unpolluted ponds was

observed repeatedly throughout the course of this study.

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